Multi skirt antenna?

I hope to get some information about multi skirt antenna.
I don't know the exact spell.

It may be multi scot, multi scat, multi scott, and so on.

I attach the shape I found and the directivity I want.

The upper directivity graph is horizontal directivity.
And the lower one is vertical directivity.

is it the periodic stripe off the outer conductor of coaxial line? I remembered in forum someone has post similar structure, I have tried to do the simulation, but the results are very very bad. If there is any more updates please share with me.

Best Regards,

This is an inexpensive way to make a phased array of half wave radiators. It is sometimes used by amateurs. The problem is that the phasing gets off if too many sections are used. It works better with air dielectric line.